Social interactions of the nocturnal primates are not well studied. One of the species for which social behavior is scarcely known is the Philippine tarsier (Tarsius [= Carlito] syrichta). We observed a reproducing pair of captive individuals over two mating seasons for two consecutive years. The tarsiers spent approximately 4% of their activity budget on social interactions; ca. 20% of time in 0–1 m proximity to each other; and shared sleeping sites for half of the study time. The majority of the animals’ social interactions were peaceful: affiliative and sexual (83%), and the smallest component of the behavior was agonistic (17%). We witnessed two copulation events (one per estrus day), each lasting ca. 5 min, and both occurring just after waking. We revealed temporal – nightly and hourly – fluctuations in the frequency of social interactions, in the distances the individuals spent from each other and in the number of vocalizations. The results present the first assessment of the social behavior of the Philippine tarsier, much needed to improve the captive breeding management for this highly sensitive species threatened with extinction.

夜间灵长类动物的社交互动尚未得到很好的研究。菲律宾眼镜猴（Tarsius [= Carlito ] syrichta）。我们观察到在两个交配季节连续两年繁殖的一对圈养个体。眼镜猴大约将其活动预算的4％用于社交互动。ca. 彼此相距0-1 m的时间为20％；并在一半的学习时间里共享睡眠场所。动物的大部分社交互动是和平的：亲和和性交（83％），行为的最小组成部分是激动性（17％）。我们目睹了两次交配事件（每个发情日一次），每次持续约。5分钟，都在醒后发生。我们揭示了社交互动频率，每个人彼此花费的距离以及发声次数之间的时间（每晚和每小时）波动。结果是对菲律宾眼镜猴的社会行为的首次评估，